See, again I will write down we have got sigma 1 and 2 is equal to minus B by A, let me say two times of that because, you know that two I can always take this side. So, that I do not have to this bottom two again B by A square minus 4 C by A, that below two was there, I took the two this side. Now, you see we want sigma 1 sigma 2 to be all negative,